To write about the career of John McGraw, both as a player and as a manager, is to write about an entire era. It's a huge story. If you want to read all the details, and I suggest you do, follow the links.
As a player he was known for his toughness. When he began, there was only one umpire per game. So when there was a chance when he knew the umpire had to be watching something else, he would assault any nearby opponent. Soon there were multiple umpires per game.
He always hit for a good average, playing in a lively-ball era, and he was able to draw a lot of walks, so his career OBP was .466, third best of all time, behind only Ted Williams and Babe Ruth.
He became player/manager of the Baltimore Orioles while he was still in his twenties. In 1902 he became a Giant. His playing career was essentially over, although he appeared in a few games now and then for a few more years.
He blew off the 1904 World Series. He thought the NY Highlanders (the Yankees' original name) were going to win the AL title and he had a major grudge against them and their owner, so he decide to not participate. (As it turned out, Boston ended up winning the AL pennant.)
Frank Deford described him thusly: he was "the model for the classic American coach--a male version of the whore with a heart of gold--a tough, flinty so-and-so who was field-smart, a man's man his players came to love despite themselves."
In thirty years managing the Giants he won 10 pennants and 3 World Series.
Topic for discussion: McGraw has been called the best player to become a great manager in major league history. Who are other candidates for that honor?